In order to make an image imaged by an imaging device, such as a digital video camera or a digital still camera, into a more interesting image, a user adds comments or sound effects to the image to create an original image. For example, a balloon may be provided in the vicinity of a face of a person in the image to write comments or a stamp may be added to highlight a motion of a person.
In a related art, when another image is added to moving image content, a user has instructed to change a display position of the additional image according to a temporal change while confirming content of moving image content in order to change the additional image according to the motion of the moving image. Also, the user has created a changed image in synchronization with the temporal change of the image moving image content in order to change the additional image according to the motion of the moving image.